Last week investors including big pharma players Novartis and Roche, as well as Manus Rogan's Fountain Healthcare Partners and Seroba Kernel Life Sciences, pumped €33m into the firm in series C financing. New backers include BB Biotech Ventures, Sunstone Capital, Baxter Ventures, Amgen Ventures, and EMBL Ventures. This brings the total amount raised by the firm to nearly €58m.

"What is important when you raise this kind of money and this kind of interest is to have good science," Opsona chief executive Martin Welschof told the Sunday Independent. "You need first- class science. That's what they are after. You won't get these kinds of investors without it."

Opsona is developing a drug that helps combat complications following kidney transplants. The market in the US and Europe could be worth close to €500m. Complications following kidney transplants are hugely expensive, with dialysis costing $35,000 per patient and a new kidney transplant up to $250,000.

Opsona was set up by O'Neill and fellow TCD scientists Kingston Mill and Dermot Kelleher. Trinity is seen as one of the world's top centres of immune system research.

The €33m raised from blue chip investors is earmarked for clinical trials, according to Welschof. The results of these trials will filter through towards the end of next year and will have a major bearing on the future direction of the company, possibly even opening the door to a stock market flotation or a trade sale.

"There are various options. For the investors, it's all about an exit. That's why they invest," said Welschof. "In the end, it's all about the data. If you have good data then you have various options. You can sell the firm, partner with someone, raise more funds or even go to the stock exchange and raise money there."

The Dublin-headquartered company may now be worth north of €100m. However , Welschof cautioned that valuations are "artificial". He added, "It depends on who you partner with or who you can sell it to. It's like sticking a finger up in the wind."

The progress of the trials in the US and Europe will be of huge interest to investors. "If you sell the company, it could be worth a few hundred million if the data is good," Welschof said.